My father is not much of a gamer, but he has always had a soft spot for the Myst series, seeing it as one of the few games he could see himself playing and genuinely enjoying. He has read all the expanded universe trilogy of it, so he is already a fan of the setting itself. I have always wanted to give him an oppertunity to play Uru, but for most of the time that it was out he did not have a computer capable of running it. A couple years ago he got a second hand still-newish iMac, which is still the best computer in my parents house.

Now, I recall hearing rumors of a Mac version of Uru in development back in the day, and I understand that GameTap offered a Mac client of it. Is that still available, and does Steam have it? If so, I would like to get a copy for my father, but I do not know how to confirm if that one of Steam's Mac offerings.

If the iMac is Intel-based (which I guess it will be if it is just a few years old - any made after 2006 are Intel), you could always use BootCamp to install Windows in a partition and run the PC version of Steam and URU from there. You'd need a full Windows disk and license though, so if you don't have one knocking about, then it's a large outlay and a bit of faff to play one game (no matter how good it is!)